[1] Univ Otago, Dept Surg, POB 4345, Christchurch, New Zealand
[2] Univ Otago, Dept Med, Christchurch, New Zealand
[3] Queen Elizabeth Hosp, Div Surg, Woodville South, Australia
[4] Univ Adelaide, Discipline Surg, Adelaide, SA, Australia
[5] Monash Univ, Dept Surg, Malvern, Vic, Australia
[6] Cabrini Hosp, Malvern, Vic, Australia
[7] Univ Sydney, Surg Outcomes Res Ctr SOuRCe, Sydney, NSW, Australia
[8] Royal Brisbane & Womens Hosp, Dept Colon & Rectal Surg, Herston, Qld, Australia